Where can I find music?

Does anybody know where I can find intermediate/beginner bass music, either on the internet or in stores (in Canada)? I've bought a couple things of sheet music, but one was too easy and the other *way* to hard. I'm going to keep trying though.
Something sort of off-topic; I found music on the internet for bass, but it has a low low C, lower than the E string. Is it possible to play that?

Music is pretty easy to find on the Internet, but I don't have any good recommendations for you.

There are basses with 5 strings, low C extensions, etc. that allow the notes below C to be played. General practice is to play the low notes an octave up in the bass section on basses that don't have access to these notes.